Extraction of Solar Coronal Magnetic Loops with the Directional 2D Morlet Wavelet Transform

An Algorithm for the Continuous Morlet Wavelet Transform

This article consists of a brief discussion of the energy density over time or frequency that is obtained with the wavelet transform. Also an efficient algorithm is suggested to calculate the continuous transform with the Morlet wavelet. The energy values of the Wavelet transform are compared with the power spectrum of the Fourier transform. Useful definitions for power spectra are given. The f...

Reconstruction of Solar Coronal Linear Force-Free Magnetic Field

The Finer Directional Wavelet Transform

Directional information is an important and unique feature of multidimensional signals. As a result of a separable extension from one-dimensional (1-D) bases, the multidimensional wavelet transform has very limited directionality. Furthermore, different directions are mixed in certain wavelet subbands. In this paper, we propose a new transform that fixes this frequency mixing problem by using a...

Nonlinear wave heating of solar coronal loops

Theheating ofmagnetically closed structures (loops) in the solar corona by the resonant absorption of incident waves is studied by means of numerical simulations in the framework of nonlinear resistive magnetohydrodynamics (MHD). It is shown that the dynamics in the resonant layer is indeed very nonlinear for typical coronal parameters. The effect of the nonlinearity on the efficiency of the re...

A Damage Detection Algorithm Using the Morlet Wavelet Transform∗

In this paper, a damage detection algorithm based on the Morlet wavelet transform of the vibration signal is presented. In the rst part of the paper, an expression for the energies of wavelet coe cients (damage sensitive feature vectors) using the Morlet wavelet basis is derived for a multi-degree of freedom system. It is shown that the energies of the wavelet coe cients extracted at higher sca...